The lifeboat was launched on Saturday after a diver got the bends while diving near the Rampion wind farm.
Shoreham RNLI launched the Enid Collett lifeboat at 6.10pm after reports the diver had been taken ill with suspected decompression sickness.
When they reached hin, he was transferred to the lifeboat, where the crew provided medical assistance while waiting for the HM Coastguard rescue 175 helicopter.
The casualty was then airlifted from the lifeboat and taken to hospital.
Lifeboat second coxswain Simon Tugwell said: “This was an excellent team effort by all those involved to provide swift medical assistance to the casualty.
“The crew were able to put into practice the skills they refreshed on a recent training scenario with the coastguard helicopter, and they really showed their knowledge and ability to help the casualty involved.”
The lifeboat returned to the station at 8pm and was washed down, refuelled and ready for service again at 8.27pm.
